An experimental and theoretical study on the reaction of Cl with CF₃CF₂CH₂OH

Abstract

An absolute kinetic study of the reaction of Cl atoms with CF 3 CF 2 CH 2 OH is reported as a function of temperature (T ¼ 268-377 K) and at a total pressure of 100 Torr by the Pulsed Laser Photolysis -Resonance Fluorescence (PLP-RF) technique. No pressure dependence of the rate coefficient for the title reaction, k, was observed between 50 and 200 Torr of He at 298 K. The derived Arrhenius expression in that T-range was k(T) ¼ (2.18 � 0.24) � 10 �12 exp(-(333 � 34)/T) cm 3 molecule �1 s �1 , where the uncertainties are �2. From these results, the average tropospheric lifetime of CF 3 CF 2 CH 2 OH due to the reaction with Cl was estimated to be 50 years, considering a global Cl concentration of 10 3 atom cm �3 and an average temperature of 272 K. Additionally, a theoretical study of the Cl þ CF 3 CF 2 CH 2 OH reaction has been carried out by ab initio Mo¨ller-Plesset second-order perturbation treatment with 6-311G** basis set to investigate the reaction mechanism. Molecular energies of the different critical points of the potential energy surface have been calculated at QCISD(T) level. The theoretical study shows that the H-atom abstraction from the -CH 2 -group is the most favourable reaction pathway.

Theoretical study of the interaction between pyridine derivatives and atomic chlorine. Substituent effect and nature of the bonding

“…The interaction between atomic chlorine or OH radical with organic molecules present in the atmosphere needs a detailed understanding as it might help in controlling the ozone depletion. The interaction of oxygen bases with atomic chlorine has been investigated in several works, for example the interaction of Cl • with H 2 O [1,2], halogenated ethers [3][4][5][6][7], methylacetate [8], halogenated aldehydes [9], fluorinated alcohols [10] and halogenated alkanes [11]. For most of these systems, such as the H 2 O. .…”

Theoretical Insight into the Kinetics of H‐Abstraction Reaction of CHF2CH2OH with OH Radical, Atmospheric Lifetime and Global Warming Potential

“…On the other hand, atmospheric lifetime is primarily determined by the rate of the reactions of HFA with the various free radicals present in the atmosphere. A number of studies have been carried out on the reactions of fluorinated alcohols with various oxidants like OH radical and Cl atoms . It is to be noted that in the theoretical studies carried out on kinetics of reactions of HFA molecules with OH radical or Cl atoms, H‐abstraction from the –CH 2 – group next to the hydroxyl (OH) group of the HFA molecule has been reported as the major reaction channel.…”